Within the Center for Biomedical Mass Spectrometry, the BUSM Mass Spectrometry Shared Instrumentation Laboratory operates two mass spectrometers (a Thermo-Fisher LTQ-Orbitrap and a Bruker Daltonics Reflex IV MALDI-TOF MS) dedicated to meeting the increasing and complex needs of NIH-funded investigators. We propose to purchase, install and operate a Thermo-Fisher 12-Tesla LC-LTQ FTMS system incorporating robotic sample handling, 1D and 2D nano-liquid chromatography, electrospray ionization, on-line Electron Capture Dissociation (ECD) and Infrared Multiphoton Dissociation (IRMPD), to provide data-dependent acquisition of high resolution-high mass accuracy spectra, increased sensitivity and reliable performance, with the goal to achieve high throughput, unambiguous identification and complete structural determinations of post-translationally modified proteins and structure elucidation of complex carbohydrates, to support the human health-related projects described in this proposal. MS and MSn spectra will be recorded online, with ECD and IRMPD dissociation and high mass accuracy being achieved in the ICR cell. The requested system will enable the Mass Spectrometry Shared Instrumentation Laboratory to implement functionality that does not exist at Boston University: that of on-line nanoLC- and high-throughput nanospray FTMS with ECD and IRMPD fragmentation. This capability will provide a group of NIH-funded investigators, whose projects are largely translational, with access to high sensitivity, high performance proteomics and glycomics analyses that focus on full characterization of post-translational modifications, including low-level phosphorylation, nitration, glycosylation and other structurally diverse and/or novel modifications which are keys to elucidating the mechanisms of complex diseases. Nine Major and four Minor research projects are proposed. All but one of these investigators are located on the BUSM campus;the other is located at Massachusetts General Hospital. PUBLIC HEALTH RELEVANCE The clinical and basic research of the Major Users includes bone resorption/ osteogenesis (Gerstenfeld), leukemia and breast cancer (Denis, Lerner), cardiovascular disease (Cohen), sickle cell disease (Steinberg), Lyme disease (Steere), infectious organisms (Samuelson and Robbins), wound healing in the eye (Trinkaus-Randall) and protein remodeling that accompanies aging and that affects drug stability (O'Connor). Projects of the Minor Users address lymphoma and breast cancer (Demierre, Seldin) and protein modifications that result in amyloid diseases and Huntington's Disease (Costello, Sherman). The proposed instrument system will accelerate progress towards understanding the mechanisms of these diseases and degenerative processes and will thus contribute directly toward improving human health.